1. Pigments are hit by photons of sunlight.
2. Sunlight energizes an electron on the pigment molecule.
3. The energized electron leaves the pigment and travels through the electron transport chain to a hydrogen ion active transport pump.
4. The hydrogen ion pump is turned on by the energized electron, and begins to pump hydrogen ions against their concentration gradient into the thylakoid membrane.
5. Hydrogen ions leave the inner thylakoid space through the ATP synthase As hydrogen ions pass through, ATP synthase is powered, allowing it to create ATP from ADP and lone phosphates
Photosynthesis uses chemiosmosis (movement of ions across a semipermeable membrane, down their electrochemical gradient) to produce energy or ATP (via ATP synthase). The movement of hydrogen ions across the thylakoid membrane in order to galvanize the production of ATP is equal to the movement of those ions across the inner mitochondria membrane.
So, during photosynthesis light energy is converted into chemical energy in the form of ATP and NADPH (electrons are accepted by the reduced electron carrier NADPH).
